Phragmites australis (Common Reed Grass) Research

Pulang ---> Phragmites australis --> Research

Competition

Holdredge, C., Bertness, M.D. Litter legacy increases the competitive advantage of invasive Phragmites australis in New England wetlands. Biol Invasions 13, 423–433 (2011). https://doi.org/10.1007/s10530-010-9836-2

Exotic plant invaders that form monocultures and exclude native plants are often the most detrimental to native diversity and the hardest to eradicate. To generate a monoculture, the invader must garner more resources than resident natives and, once established, persist despite high densities of conspecific neighbors. Coincident with expansion and long-term persistence, successful invaders typically accumulate senesced material, but the role of this litter in mediating the invader’s ability to establish and maintain monospecific dominance has rarely been investigated. We used stands of the common reed, Phragmites australis, a prolific wetland invader in North America, to explore the impact of litter on interspecific competition with the native rush, Juncus gerardii, and intraspecific competition among live shoots. In 10 × 10 m areas positioned on Phragmites expansion fronts, we removed litter to isolate its effect from live Phragmites on light availability, aboveground biomass and community composition. Compared to adjacent, unmanipulated fronts, light availability nearly tripled and Juncus biomass increased >170% in litter removal areas after 4 months. Although the positive response of Juncus and native forbs was most pronounced on the leading edge of Phragmites stands, litter removal triggered a 271% increase in native plant biomass even in the interior of stands where Phragmites’ live stem density was highest. Litter treatment did not significantly affect Phragmites biomass, but more, shorter stems emerged in litter removals revealing Phragmites modifies stem phenotype in response to local litter and light conditions. These results suggest that litter plays a central role in Phragmites’ invasion process, from initial establishment to subsequent monospecific dominance. Thus, prescribed litter removal may be an effective strategy to enhance coexistence of native plant populations in wetlands where eradication of invasive monocultures is not an ecologically or economically feasible option.

Legault R II, Zogg GP, Travis SE (2018) Competitive interactions between native Spartina alterniflora and non-native Phragmites australis depend on nutrient loading and temperature. PLoS ONE 13(2): e0192234. https://doi.org/10.1371/journal.pone.0192234

We explored the nature and impact of competitive interactions between the salt marsh foundational plant Spartina alterniflora and invasive Phragmites australis in New England under varying levels of anthropogenic influence from nutrient loading and temperature warming. Plants were grown with and without competition in mesocosms over a four-month growing season. Mesocosms were split evenly among three levels of nutrient additions and two temperatures varying by an average of ~3° C, manipulated using small greenhouses. We measured aboveground productivity as total biomass, numbers of new stems, and mean stem height. Nutrient enrichment increased all growth parameters, while competition generally reduced aboveground biomass and the production of new stems in both species. Most importantly, smooth cordgrass suffered no negative consequences of competition when no nutrients were added and temperature was elevated. The results of this study suggest that minimizing nutrient loading into coastal marshes could be an important factor in slowing the spread of common reed into the low marsh zone of New England salt marshes as global temperatures continue to warm.

Summaries and Reviews

Attila I. Engloner, Structure, growth dynamics and biomass of reed (Phragmites australis) – A review, Flora - Morphology, Distribution, Functional Ecology of Plants, Volume 204, Issue 5, 2009, Pages 331-346, ISSN 0367-2530, https://doi.org/10.1016/j.flora.2008.05.001.

This paper reviews about 190 publications related to the anatomy, morphology and growth of aboveground and belowground parts of common reed (Phragmites australis). In addition to the general description of plant structure, observations on germination, growth dynamics, biomass, effects of habitat conditions such as temperature, salinity, nutrient supply and water depth are evaluated. The impact of animal, fungal and algal attacks, and human intervention (burning and harvesting) on reed growth, and the potential genetic determinacy behind the response of reed to environmental changes are also discussed.

Penulis: A. Sunjian